#include<bits/stdc++.h>
#define int long long
#define endl "\n"
#define PII pair<int,int>
using namespace std;
const int maxn = 1e5 + 5;
vector<int> temp[maxn];
signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0); std::cout.tie(0);
    int T; cin >> T;
    while (T--) {
        int n; cin >> n;
        vector<int> a(n + 1);
        map<int, int> m;
        for (int i = 1; i <= n; ++i) {
            cin >> a[i];
            temp[i].clear();
        }
        int kase = 1;
        for (int i = 1; i <= n; ++i) {
            if (m[a[i] - i]) {
                temp[m[a[i] - i]].push_back(a[i]);
            }
            else {
                m[a[i] - i] = ++kase;
                temp[kase].push_back(a[i]);
            }
        }
        int ans = 0;
        for (int i = 1; i <= kase; ++i) {
            if (temp[i].size() < 2) continue;
            for (int j = temp[i].size() - 1; j > 0; j -= 2) {
                if (temp[i][j] + temp[i][j - 1] < 0) break;
                ans += temp[i][j] + temp[i][j - 1];
            }
        }
        cout << ans << endl;
    }
    return 0;
}